A. V. Petrovskaya

Relationships and divergence of some taxa of the subfamily Lycodinae (Zoarcidae, Pisces) based on molecular-genetic and morphological data

An integrated molecular-genetic and morphological study of 14 species of 6 genera of Zoarcidae of the subfamily Lycodinae was performed. A high coincidence of study results obtained using both methods was found. The generic independence of the genus Petroschmidtia that includes species P. albonotata and P. toyamensis was justified. It was shown that species L. schmidti and L. nigrocaudatus belong to the genus Lycogrammoides; and the generic status of the genus Bothrocarichthys with species B. microcephalus and of the genus Allolepis with species A. hollandi was restored. The studied taxa fall into three large monophyletic groups that include species of the genus Petroschmidtia, species of the genus Lycodes, and species of the genera Bothrocara, Allolepis, Bothrocarichthys, and Lycogrammoides. Taxa of the last group are characterized by a large complex of morphological differences from the first two groups, including the absence of ventral fins. A key to species and genera of Lycogrammoides and Bothrocarichthys was compiled. The problem of determination of the time of divergence of the studied zoarcid-like fish using the concept of “molecular clock” and its calibration according to paleontological and paleogeographic data is discussed.

Intraspecific structure of sable Martes zibellina L. Inferred from nucleotide variation of the mitochondrial DNA cytochrome b gene

A fragment of the mitochondrial DNA (mtDNA) cytochrome b gene was sequenced in sable from Magadan oblast, Khabarovsk krai, and Kamchatka. Using phylogenetic analysis, the presence of two clusters (A and BC), with the divergence value of 1.4%, was demonstrated. Analysis of the cytochrome b gene median networks indicated that split of the ancestral population took place in early Pleistocene (about one Myr ago), while expansion of its more young phylogenetic group A occurred in late Pleistocene, about 120000 years ago.

Relationships and position of the genus Neozoarces of the subfamily neozoarcinae in the system of the suborder Zoarcoidei (Pisces, Perciformes) by molecular-genetic data

Using the method of molecular-genetic analysis, we investigated the genus Neozoarces (subfamily Neozoarcinae) to reveal its relationships and position in the system of the suborder Zoacoidei. Comparison with representatives of other families of this suborder demonstrated that the lowest level of differences is observed between Neozoarces and subfamilies of the family Zoarcidae (the mean value of genetic divergence is 11.9%) with which it forms a general cluster on the phylogenetic tree. From representatives of the family Stichaeidae, Neozoarces differs at the same level (13.9%) as from the families Bathymasteridae, Pholidae, Ptilichthyidae, and Zaproridae (14.0%). The results of investigations confirm the viewpoint suggested by Makushok (1961) who included, for the first time, the subfamily Neozoarcinae to the family Zoarcidae on the basis of comparative morphological investigation of these groups.

Genetic structure of the sable Martes zibellina L. populations from Magadan oblast as inferred from mitochondrial DNA variation

Restriction polymorphism of the mtDNA cytochrome b gene was studied in nine sable Martes zibellina L. populations from three introduction foci of Khabarovsk and Kamchatka sables in Magadan oblast: Olya, Kolyma, and Omolon. For comparison, similar studies were performed with the populations of central Kamchatka and Khabarovsk krai. In total, 444 DNA specimens were examined. Three mtDNA haplotypes (A, B, and C) proved to occur at various frequencies in the populations under study. The sable population system displayed high differentiation (FST = 22.3%). The populations of the Olya focus were most similar genetically to the populations of Kamchatka; those of the Omolon focus were similar to the Khabarovsk populations, and those of the Kolyma focus occupied an intermediate place. The observed spatial heterogeneity of the sable populations of Magadan oblast was explained in terms of the formation of the introduction foci of Kamchatka and Khabarovsk sables, starting from the 1950s.

Relationships and position of wrymouths of the family cryptacanthodidae in the system of the suborder Zoarcoidei (Pisces, Perciformes)

To determine the taxonomic position of wrymouths of the family Cryptacanthodidae in the system of the suborder Zoarcoidei, a study on molecular genetics and comparative morphology of Cryptacanthodes bergi from Peter the Great Bay (Sea of Japan) is conducted. Based on molecular genetic analysis using the genes of nuclear and mitochondrial DNA, Cryptacanthodes bergi is substantially similar to the representatives of the superfamily Stichaeoidae. Thus, the opinion of Makushok on a phylogenetically distinct position of wrymouths in relation to snake blennies and related families is not supported. The anatomical features of skull structure support the data of molecular genetics. The directions and time of distribution of wrymouths in the northwest Atlantic through the channel in the area of the Isthmus of Panama in approximately the late Miocene are discussed.

Relationships and position of the taxa of the subfamily Xiphisterinae in the system of the suborder Zoarcoidei (Perciformes)

Analysis of the nucleotide sequences of mitochondrial and nuclear DNA genes was used to examine the relationships and position of the subfamily Xiphisterinae in the system of the suborder Zoarcoidei. This study showed the genetic heterogeneity of Xiphisterinae and the propriety of its division into two subfamilies: Xiphisterinae with the genera Xiphister and Phytichthys and Cebidichthyinae with the genera Cebidichthys, Dictyosoma, Esselenichthys, and Nivchia. The genetic differences between the two subfamilies were not less, but in some cases even greater than the differences between families within the suborder; therefore, they should be raised to the rank of a family, Xiphisteridae and Cebidichthyidae, and classified not within the superfamily Stichaeoidae but rather as independent taxa of the suborder Zoarcoidei.

Position of neck banded blenny Leptostichaeus pumilus (Perciformes: Zoarcoidei) in the system of the suborder Zoarcoidei as inferred from molecular genetic data

Molecular genetic study of genetic variations within COI, cytochrome b, and 16S rRNA of mitochondrial DNA in neck banded blenny Leptostichaeus pumilus, which was earlier assigned to the family Stichaeidae, indicates that the species is most close to a group combining the families Zoarcidae, Neozoarcidae, and Anarhichadidae. Significant genetic differences between neck banded blenny and the family Stichaeidae correspond to the level of divergence between other families of the suborder Zoarcoidei (Zaproridae, Ptilichthyidae, Pholidae, Cryptacanthodidae, and Bathymasteridae).

Phylogenetic relations in the family pholidae (Perciformes: Zoarcoidei) based on genetic and morphological data

Molecular-genetic study of Pholidae of the suborder Zoarcoidei was first performed. Analysis of variation of genes of COI, cytochrome b, and 16S rRNA of mitochondrial DNA indicates different phylogenetic isolation of the family taxa. The groundlessness of separating subgenera (or genera) Enedrias and Allopholis and the rightfulness of including them in the composition of the genus Pholis are shown. Genetic close relation of the genera Pholis and Rhodymenichthys and their differences from the genus Apodichthys are established. The obtained results agree with the data of Makushok (1958) who separated in the composition of the family two subfamilies—Pholinae (with genera Pholis and Rhodymenichthys) and Apodichthyinae (with the genera Apodichthys, Xererpes, and Ulvicola). A key to species, genera, and subfamilies of gunnels of the northern part of the Pacific Ocean is provided.

Restriction Fragment Variation of the Mitochondrial Gene of Cytochrome b in Some Taxa of the Eelpout Family (Pisces, Perciformes, Zoarcidae) from the Northern Sea of Okhotsk

The first analysis of restriction fragment length polymorphism (RFLP) of the mitochondrial gene of cytochrome b of fish from the Eelpout Family (Zoarcidae) from the northern Sea of Okhotsk has been performed. The mean genetic distances between the subfamilies Zoarcinae and Lycodinae, subfamilies Lycodinae and Gymnelinae, and subfamilies Zoarcinae and Gymnelinae are 11.14, 13.87, and 14.00%, respectively. Species of the genus Lycodes (Lycodinae) are characterized by a mtDNA small divergence (on average, 2.04%) and are divided into two groups on the basis of lateral line morphology. Magadania skopetsi, an endemic of Tauiskaya Bay of the Sea of Okhotsk, is genetically close to Hadropareia middendorffii from the same subfamily (Gymnelinae). The mtDNA sequences of species from the genus Lycogrammoides (Lycodinae) differ by 3.83%. The genetic differences between the eelpout Zoarces elongatus Zoarces sp. (d = 4.54%) suggest that the latter is a separate species.

Relationships of eelpouts of the genus Zoarces (Zoarcidae, Pisces) inferred from molecular genetic and morphological data

Abstract-Molecular genetic and morphological analysis of eelpouts of the genus Zoarces was carried out. Based on the mitochondrial DNA sequence variation, haplotypes of notched-fin eelpout, Z. elogatus, more closely related Fedorov eelpout, Z. fedorovi, and common eelpout, Z. viviparus, as well as of Andriyashev eelpout, Z. andriashevi, were grouped in one macrocluster. Haplotypes of American eelpout, Z. americanus, and blotched eelpout, Z. gillii, clustered separately from other species. The genetic differences between Z. gillii and the other eelpout species were very high for within-genus comparisons, constituting 7.62%. Species divergence in terms of morphological characters was generally consistent with molecular genetic data and confirmed distinct isolation of American eelpout, and especially of blotched eelpout.